Synthesis of nanocrystalline CuFeO2 by ion-exchange method and its applications on hydrogen generation via visible-light-driven photocatalytic water splitting

• Main Authors: Hung-ming Chen, 陳泓明
• Other Authors: Bing-joe Hwang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/13078613418993698315

碩士 === 國立臺灣科技大學 === 化學工程系 === 98 === Nanocrystalline CuFeO2 has been synthesized successfully by ion-exchanging molten CuCl with layer-structured ??NaFeO2. Crystal structure and domain size of CuFeO2 were characterized by XRD and TEM. Optical properties of CuFeO2 were determined by visible-infrared spectrum as well. In addition, Z-scheme photocatalytic water splitting without electron mediator carried out in a fluidized-bed photocatalyst reactor with as-synthesized CuFeO2 and Bi20TiO32 powder is proposed and measured in the present work. First, nanocrystalline ??NaFeO2 was synthesized successfully by thermal decomposition of EDFS under the air flow of 1 L/min and calcinations at 530 ℃ twice. The grain size of ??NaFeO2 is measured about 5 ~ 10 nm by TEM. High crystallinity of ??NaFeO2 results from suppressing the formation of ??NaFeO2 under sufficient O2 condition. Next, nanocrystalline CuFeO2 was synthesized successfully by ion-exchange method and domain size of CuFeO2 is about 5 ~ 10 nm determined by TEM. Domain boundaries of CuFeO2 result from sintering of grains in molten CuCl. Crystal growth of CuFeO2 is more significant in direction of a axis and b axis when operating temperature of molten CuCl increases. Near-IR absorbance of CuFeO2 increases slightly with increasing dimension of the plane in c axis. The H2 production from the system could not be successfully detected. One reason could be attributed to the serious recombination of photon-generated electrons and holes at the grain boundaries of CuFeO2.